Association of retinal vessel caliber and visual field defects in glaucoma

- PURPOSE: This study evaluates the asymmetry of peripapillary retinal vess el caliber between inferior and superior hemispheres in eyes with visual fi eld defects predominantly in one hemifield. - DESIGN: Observational case series. - METHODS: In a retrospective study, 64 eyes of 64 patients with primary op en-angle glaucoma who had a marked difference in visual field defects betwe en hemifields and who had no history of diabetes, trauma, or vascular occlu sive disease were studied. The diameters of the superior and inferotemporal vessels were measured at the optic disk border with calipers on an enlarge d image. - RESULTS: In 64 eyes, the average ratio of the superior temporal artery di ameter to inferotemporal artery diameter was significantly greater in the e yes with predominantly superior visual field defects as compared with those with inferior defects (1.10 +/- 0.22 vs. 0.92 +/- 0.19, respectively, P = .002, two,tailed t test). This indicates that the arteriole corresponding t o the hemifield with the greater visual field defect was narrower than the arteriole in the other hemifield. This relationship was confirmed using chi (2) analysis (P = .002) comparing the proportions of eyes with ratios grea ter or less than normal vessel caliber ratios (normal ratio = 0.95 from dat a reported by Jonas and associates to the location of the dominant field de fect. No statistically significant relationship was detected between retina l vein diameter and localized visual field defects, as determined by both t he unpaired t test and chi (2) analysis. - CONCLUSION: In eyes with primary open,angle glaucoma, this study demonstr ates a strong association between decreased peripapillary arteriole diamete r and visual field defects in the corresponding hemifield. This reflects ei ther an ischemic basis for glaucomatous damage or vascular constriction whe n there are fewer axons to nourish. (C) 2001 by Elsevier Science Inc. All r ights reserved.